1. Field of the Invention
The present invention relates to a tactile sensor and a manufacturing method thereof, and more particularly to a tactile sensor for curved surfaces, wherein metal layers and resistors are formed on upper and lower films with excellent bending property and high restoration force, respectively, and the upper and lower films are perpendicularly bonded to each other, thereby increasing flexibility to be applicable to objects with multi-dimensional curvature and a small radius of curvature and a manufacturing method thereof.
2. Description of the Related Art
Recently, a tactile function for obtaining information regarding circumferential environment through touch, for example, a contact force, vibration, surface roughness, heat conductivity versus temperature change and the like has been used for advanced information collection. A biomimetic tactile sensor capable of replacing tactile sensation can be used for microsurgery of blood vessels, various medical diagnoses such as a cancer diagnosis and treatment. Further, the biomimetic tactile sensor can be applied to tactile display technology which is important in virtual environment technology in the future.
Sensors developed as the biomimetic tactile sensor include a force-torque sensor with six degrees of freedom which is used on a wrist of an industrial robot and a sensor used for a gripper of a robot, capable of sensing a contact pressure and instantaneous sliding motion. Such sensors have a relatively large size, thereby having a problem such as low responsiveness.
A possibility of developing the tactile sensor has been verified using technology for manufacturing micro electro mechanical systems (MEMS). However, since the sensor has been developed using a silicon wafer and the like, the sensor does not have flexibility.
FIG. 17 shows an example of a conventional tactile sensor, which is developed by Takao Someya and colleagues at the University of Tokyo in Japan in 2005.
In this case, the conventional tactile sensor is manufactured by performing a punching process on a single film, thereby realizing flexibility and extensity to some extent.
However, the conventional tactile sensor manufactured through the punching process fails to maximize flexibility because a single film is punched for flexibility. Thus, it is possible to apply the conventional tactile sensor to spherical objects with a large radius of curvature. However, it is hard to apply it to fingers of a humanoid robot or a very small sphere due to a lack of softness like human skin.